Field of the Invention
The present disclosure relates to an element substrate that ejects a liquid, a liquid ejection head, and a liquid ejection apparatus.
Description of the Related Art
An element substrate that ejects a liquid is typically included in a liquid ejection head used in a liquid ejection apparatus, such as an ink jet printer. An element substrate including a structure in which a plurality of members are layered is known.
In a liquid ejection head disclosed in Japanese Patent Laid-Open No. 62-111758, a member including ejection ports that eject a liquid, a member including pressure chambers that retain the liquid ejected from the ejection ports, a member including liquid flow passages that are in communication with the pressure chambers, and a member that generates energy to eject the liquid are layered.
When the members described above are adhered together with an adhesive agent, typically, the adhesive agent is applied to the adhesion surface of each member and the members on which the adhesive agent has been applied are pinched and pressed. In so doing, the adhesive agent is pushed out from the adhesion surface of each member, and there are cases in which the adhesive agent that has been pushed out enters the ejection ports and the liquid flow passages and becomes cured. In such a case, a portion or all of the ejection ports and the liquid flow passages become clogged with the cured adhesive agent, effecting the flow of the liquid such that flow of liquid is retarded extremely reducing the flowing amount of liquid. As a result, there may be cases in which the desired liquid ejection volume cannot be reached.
As a measure for the above, one may conceive a method of suppressing the adhesive agent from being pushed out by restricting the application area of where the adhesive agent is applied and by restricting the application amount. However, with such a method, there may be an area with insufficient adhesion and the liquid may leak from that area. In the above case, when ejection ports that eject liquids of different colors are adjacent to each other, the liquids that have leaked from a portion near the ejection ports may come in contact with each other causing color mixing to happen. As a result, degradation in the image quality of the recorded image may occur.
Accordingly, there are many element substrates with relief grooves for releasing the adhesive agent, which has been pushed out, formed in portions around the ejection ports and the liquid flow passages. In such a type of element substrate, since it is possible of suppress the adhesive agent that has been pushed out from entering the ejection ports and the liquid flow passages, even if there is no restriction in the application area and the application amount, the flow of the liquid can be kept at a normal state.
In recent years, due to an increase in the quality and speed of recording, the element substrate is required to increase the number of ejection ports, and due to this, ejection ports are required to be disposed at a high density. However, when the election ports are disposed at a high density, the pressure chambers and the liquid flow passages need to be disposed at a high density as well, such that the gap between the adjacent pressure chambers and adjacent liquid flow passages become small, making it difficult to sufficiently form the relief grooves of the adhesive agent around the ejection ports and the liquid flow passages. Accordingly, trouble such as leakage of liquid may occur due to having difficulty in maintaining the flow of the liquid at a normal state, and due to restricting the application area and the application amount of the adhesive agent to maintain the flow of the liquid at a normal state.